Low back pain is a common clinical complaint, and most people with low back pain may first think of lumbar strain and lumbar disc herniation. I once saw an article written by a “famous doctor” who treats low back pain in China, the title of the article is quite radical, I forgot exactly how it was written, but the content was intended to fool patients by making lumbar disc herniation the main cause of low back pain. The first thing I felt after reading the article was that either the author of the article was fooling the patients, or he did not have a deep understanding of herniated discs. In fact, if you Google the causes of low back pain, you can find quite a lot of articles introducing it, but there are very few systematic introductions, most of them are for a specialized field. Here I will list the causes of low back pain roughly, according to the etiology into the following categories: 1, trauma: including acute or chronic injury to the muscles of the low back caused by acute and chronic trauma, injury and fracture of the vertebrae and accessories of the spine. For patients with osteoporosis, very minor trauma or no obvious traumatic factors can lead to vertebral fractures and result in pain. Chronic injury leading to muscle strain, chronic ligament injury, interspinous ligament injury, etc. can lead to low back pain; 2, degenerative spinal lesions: such as osteophytes, herniated discs, ligamentous hypertrophy, etc. can lead to spinal stenosis, nerve root compression and low back pain symptoms; small joint degeneration of the vertebral body, joint dysfunction, vertebral slippage, etc. can also lead to low back pain; 3, spinal dysplasia: such as bony spinal canal 3, spinal dysplasia: such as bony spinal stenosis, lumbar sacralization, unilateral lumbar transverse hypertrophy and sacro/iliac joint formation, congenital discontinuity of the vertebral arch, spondylolisthesis, spinal hyperplasia, etc., scoliosis, vertebral developmental deformities such as hemivertebrae, butterfly vertebrae, etc.; 4, immune diseases or systemic diseases: such as ankylosing spondylitis, sclerosing sacroiliac arthritis, etc.; 5, spinal tumors or tumor-like lesions: such as vertebral hemangioma, myeloma, aneurysmal bone cysts, metastatic tumors, giant cell tumors, eosinophilic granulomas, etc.; 6, intraspinal lesions: extraspinal tumors such as neurofibromas, nerve sheath tumors, spinal meningiomas, epidermoid cysts, vascular malformations, etc.; 7, vertebral infectious lesions: such as vertebral tuberculosis, vertebral inflammation, disc inflammation, etc.; 8, retroperitoneal lesions: such as retroperitoneal tumors, lymph node enlargement or tumor metastasis, pancreatic cancer, cholecystitis or gallbladder stones, and 9, reproductive system lesions: gynecological such as pelvic inflammatory disease, adnexitis, pelvic stasis, posterior uterine tilt, uterine fibroids, etc.; men’s prostatitis, seminal vesicle adenitis, etc.; 10, endocrine system diseases: osteoporosis, hyperparathyroidism, etc.; 11, toxic diseases: fluorosis, etc. Since there are too many diseases that can cause low back pain, clinicians need to rule out the lesions one by one based on the patient’s complaints, age, occupational characteristics, onset time, clinical manifestations, physical examination, laboratory tests and imaging examinations. The above diseases are only the common diseases that need to be ruled out clinically, and there are some rare diseases which have involved orthopedics, rheumatology, gynecology, urology, oncology, endocrinology, Chinese medicine surgery or rehabilitation, interventional therapy, etc. It is obvious that their diseases are not as simple as we think. I have consulted many patients with low back pain, which have been treated as lumbar disc herniation, and later clarified as vertebral body tumor, intravertebral canal tumor, intravertebral canal vascular malformation, vertebral tuberculosis, etc. by magnetic resonance examination respectively, and also some people have retroperitoneal tumor. Therefore, when the common single symptom of low back pain is present, multiple tests may be required to determine the cause. And the patient has to understand why the doctor would prescribe a bunch of tests for himself, because the learning behind this simple low back pain is really too big!